In the UK, Draught Beer must be sold in Officially Measured Pint Glasses

In the United Kingdom, draught beer must be sold in Imperial measure (see Pint#Effects of metrication). United Kingdom law requires certain steps be taken to ensure that a pint of beer is indeed a pint. Though this can be achieved using "metered dispense" (calibrated pumps), the more common solution is to use certified one-pint glasses[citation needed]. Until recently these had a crown stamp and number etched upon them indicating that the certification had been done by an agency of the Crown.
@Curionic